This invention relates to a navigation system for cars which provides an indication for guiding a car to a destination.
In the conventional navigation system generally used for cars, a liquid crystal display or a CRT (Cathode Ray Tube Display) is used as an indicator in which a map representing the car's present position is shown. Accordingly, the driver inputs the present position and the destination using a position input key such as a cursor key or the like while observing an indicator. Then, an internal arithmetic unit calculates the shortest course automatically and shows the course on the indicator. The driver can then manually change the course, partially or totally. In addition, a different course can also be selected from the first.
In this state, when the car starts, the arithmetic unit calculates the present position to indicate the position on the map. The driver observes the indication to drive the car toward the destination.
Further, roughly classified, there are two detecting means for detecting the above present driving position. One is to perform it with a direction sensor which detects the driving direction of the car and a distance sensor which detects the driving distance of the car. Another is to detect the driving position by receiving a signal from an artificial satellite by both sides of the car.